The present invention relates to a heat sink for use in a computer for dissipating heat, and more particularly to such a heat sink which is inexpensive to manufacture and, which provides extended air contact area for quick dissipation of heat.
A regular computer heat sink, as shown in FIG. 1, is extruded from aluminum, having a plurality of radiating fins. Because the heat sink is extruded from aluminum, the height of the radiating fins is limited, and the thickness of the radiating fins can not be reduced to the desired level. Because the radiating fins have a certain thickness, much aluminum material is used, and the manufacturing cost of the heat sink is high. FIG. 2 shows another structure of heat sink according to the prior art. This structure of heat sink comprises a flat base plate, and a plurality of radiating fins having respective mounting flanges respectively bounded to the flat base plate. Because the radiating fins are fastened to the flat base plate by bounding, a long drying procedure is needed. Therefore, the fabrication speed is slow. Further, because the radiating fins are bounded to the flat base plate by labor, it is difficult to control the bounding quality. FIG. 3 shows still another structure of heat sink according to the prior art. This structure of heat sink comprises a flat base plate, and a plurality of single layer radiating fins formed integral with the top side wall of the flat base plate. Because the heat sink is made by die casting, the bottom side wall of the flat base plate is uneven, and must be processed again after die cating. This die casting manufacturing method can not achieve a satisfactory productivity. Furthermore, the fraction defective of die casting is high.
The present invention has been accomplished to provide a heat sink which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a heat sink which is easy and inexpensive to manufacture. It is another object of the present invention to provide a heat sink which achieves satisfactory heat dissipation performance. To achieve these and other objects of the present invention, a heat sink is provided comprises of a flat base having elongated coupling grooves and upright cylindrical sockets in the coupling grooves, a plurality of U-shaped radiating fins respectively mounted in the elongated coupling grooves at the flat base plate, and a holding down plate covered on the flat base plate to hold down the radiating fins. The holding down plate has insertion slots through which side walls of the U-shaped radiating fins pass, and through holes respectively fastened to the upright cylindrical sockets at the flat base plate by rivets.